1. Field of the Invention
The present invention relates to a casting apparatus.
2. Description of the Related Art
In the field of die casting machines and other casting apparatuses, it is necessary to heat and melt metal from a solid state and feed the molten metal to the casting apparatus. As the method for heating and melting the metal, the technique of using induction heating to melt the metal and feeding that molten metal to the casting apparatus has been known. Induction heating is a method of heating metal for use for casting by inducing a current through the metal by electromagnetic induction and heating the metal by the Joule heat generated at that time.
On the other hand, a melted metal material is usually extremely high in temperature compared with the surroundings and is difficult to handle when feeding it to a casting apparatus. For example, with the method of scooping out melted metal material by a ladle to feed it to the casting machine, the metal material may solidify and oxidize.
As another method, for example, Japanese Unexamined Patent Publication (Kokai) No. 2001-239354 discloses a molten metal feed apparatus using induction heating to melt metal in a cylindrical furnace provided facing the cylinder of an injection apparatus and feeding that molten metal into a die casting machine.
The above molten metal feed apparatus is provided with an opening for ejecting the molten metal formed at the bottom of the cylindrical furnace into the cylinder and a lid for opening and closing the opening. By sliding the lid to open the opening, the molten metal in the cylindrical furnace flows into the cylinder by gravity.
This molten metal feed apparatus can feed the necessary amount of the molten metal into the injection apparatus without contact with air and can thereby maintain the quality of the molten metal.
With the molten metal feed apparatus disclosed in the above publication, however, there is a possibility of the molten metal in the furnace leaking out from the clearance formed between the opening and the lid closing that opening. If molten metal in the furnace leaks out, opening and closing of the lid will become difficult and the ladling quantity of the molten metal fed into the die casting machine may be dispersed.